Electrical relay



A HUFNAGEL May 9, 1939 ELEC TR I CAL RELAY Filed March 18, 1937 INVENTOR agQl And ow HIS ATTORNEY Patented May 9, 1939 UNITED STATES PATENT OFFICE ELECTRICAL RELAY Application March 18, 1937, Serial No. 131,612

12 Claims.

My invention relates to electrical apparatus, and particularly to electrical apparatus of the type for making and breaking circuits. More specifically, my invention relates to contacting devices utilizing. electro-conductive liquid and to means for controlling the liquid by passing magnetic flux and electric current through the liquid.

I shall describe several forms of electrical apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view illustrating one form of electrical apparatus embodying my invention. Fig. 2 is a front diagrammatic view of the contacting l5 device shown in Fig. l, and Fig. 3 is a sectional view taken along the line HI]1I of Fig. 2. Fig. 4 is a diagrammatic view illustrating another form of electrical apparatus embodying my invention. Fig. 5 is a front diagrammatic view of the contacting device shown in Fig. 4, and Fig. 6 is a sectional view taken along the line VI-VI of Fig. 5. Fig. 7 isa diagrammatic view illustrating still another form of electrical apparatus embodying my invention. Fig. 8 is'a front 3 diagrammatic view of the contacting device shown in Fig. 7, and Fig. 9 is a sectional view taken along the line IXD of Fig. 8. Fig. 10 is a diagrammatic view illustrating still a different form of electrical apparatus embodying my invention. Fig. 11 is a front diagrammatic view of the contacting device shown in Fig. 10, and Fig. 12 is a sectional view taken along the line )HIXII of Fig. 11.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1, 2, and 3, the reference character I designates an elongated receptacle containing a globule 2 of an electro-conductive liquid which is preferably mercury and which is free to move in a path between the ends of the receptacle.

I provide means for passing magnetic flux and means for passing electric current through the mercury. As here shown, the means for passing magnetic flux through the mercury is a U-shaped permanent magnet 3 with its poles on opposite sides of and in close proximity to the surface of receptacle I. It will be seen, therefore, that nearly all of the magnetic flux will pass through the path of the mercury globule and that the direction of this flux is vertical. The means for passing electric current through the mercury includes two electrodes 4 and 5 located in one end of the receptacle l and electrodes 6 and 1 located in the other end of the receptacle. It will be apparent that when the globule of mercury is in the left-hand end of the receptacle, electrodes 4 and 5 will' be bridged and that when the globule of mercury is in the right-hand end of the receptacle, electrodes 6 and I will be bridged. The path of the current flowing from one terminal to the other through the mercury is, therefore, horizontaL that is, at right angles to the path of the magnetic flux.

Electrodes 5 and 6 are connected to one terminal of a source of energy, here shown as a battery 8, and electrodes 4 and 1 are connected to one terminal of loads 9 and I0, respectively. As here shown, the loads are electric lamps. The other terminals of lamps 9 and ID are connected by a switch S to the other terminal of battery 8.

When either the magnetic fiux or the electric current, or both, are absent, the globule I will remain stationary. When, however, the magnetic flux and the electric current are both present, the globule of mercury will be caused to move in one direction or the other. The direction of the flow of mercury depends on the relative direction of the magnetic flux and the electric current, and a reversal of either one will cause a reversal of the direction of movement of the mercury. Since the magnet 3 is a permanent magnet and, therefore, provides a magnetic flux which always flows in the same direction it follows that the direction of movement of the mercury globule may be governed by controlling the direction of electric current through the mercury.

When switch S is closed, electric current will flow through globule 2 from electrode 5 to electrode 4 over a circuit which includes lamp 9. This flow of electric current coacting with the magnetic flux will propel the globule 2 to the right end of receptacle I so that electrodes 6 and 1 are bridged instead of electrodes 4 and 5. This extinguishes lamp 9 and passes electric current through the mercury in the opposite direction from electrode 6 to electrode 1 so that lamp l0 becomes lighted. The reversal of the direction of electric current through the mercury propels the globule back to the left-hand end of the receptacle thus extinguishing lamp ID and bridging electrodes 4 and 5 to again light lamp 9 and pass current through the mercury in the initial direction. It will be seen, therefore, that as long as switch S remains closed, the globule 2 will be propelled back and forth between the ends of receptacle I to cause lamps 9 and I0 to become alternately lighted.

Referring next to Figs. 4, 5, and 6, receptacle l is suitably supported in an inclined position by means not shown in the drawing so that globule 2 rests in the lower end of the receptacle. At the lower end of the receptacle is a short electrode H and a long electrode I 2, that is, electrode 52 extends the entire length of the receptacle so that globule 2.is always in engagement with that electrode. When switch S is closed, current will flow from the positive terminal of battery 8 to electrode l2, thence through globule 2, electrode II, and lamp 9 back to the negative terminal of battery 8 so that lamp 9 will become lighted. The current passing through the mercury globule coacting with the magnetic flux supplied by magnet 3 will propel the globule towards the other end of the receptacle so that electrodes II and i2 will be no longer bridged. With electrode ll out of engagement with globule 2, the current flow will be interrupted to extinguish lamp 9 and to permit the globule to return to the lower end of the receptacle so that the cycle of operation just described will be repeated as long as switch S remains closed. It will be noted that since globule 2 is always in engagement with electrode l2, which is in turn connected to the positive terminal of battery 8, the globule is positively charged so that the drawing of an are between globule 2 and short electrode-l I is prevented. This insures that the current will be interrupted completely and quickly as globule 2 moves out of engagement with electrode II.

If desired the apparatus shown in Figs. 4, 5, and 6 may be used as a current overload limiting device by simply reversing the poles of the permanent magnet and the connections of the battery 8 so that globule 2 will be negatively charged. Considering that lamp 9 is a variable load, the apparatus will then be adjusted so that the current normally required by the load will not be sufflcient to propel the globule out of engagement with electrode l I. When an overload occurs, the increased current flow will cause the globule 2 to move toward the other end of the receptacle, and, since the globule is now negatively charged, an arc will be drawn to maintain the current through the globule at a reduced rate. Thus, the current through the load will be limited and the globule will be maintained in the. upper end of the tube until such time as the overload is removed or the switch S is opened.

Referring next to Figs. 7, 8, and 9, the means for passing magnetic fiux through themercury in the receptacle is here shown as an electromagnet l4 with a winding having a right-hand portion l5 and a left-hand portion IS. The reference character I! denotes a movable contact which may be controlled in any desired manner to engage with either contact I 8 or contact l9. When or the other to propel the mercury globule in either direction. I

When the switch S is closed, energy will fiow simultaneously through two circuits to energize winding l 5 in one direction and to energize lamp 9 through electrodes 4 and 5 and globule 2. The circuit for winding l5 may be traced from the positive terminal of battery 8 through switch S, winding l5, and contact l'I-Hl to the negative terminal of battery 8. The circuit for lamp 9 may be traced from the positive terminal of battery 8 through switch S, electrode 5, globule 2, electrode 4, and lamp 9 to the negative terminal of battery 8. The current passing through the mercury coacting with the magnetic flux generated by the energization of winding I5 will propel the globule 2 to the opposite end of the receptacle. When the globule becomes out of engagement with electrodes 4 and 5, current will be disconnected from lamp 9 but, when the globule bridges electrodes 6 and 1, lamp ID will become lighted. The circuit for lamp I may be traced from the positive terminal of battery 8 through switch S, electrode 1, globule 2, electrode 6, and lamp ID to the negative terminal of battery 8. Since the current supplied to lamp ID will be moving through the globule in the same direction as the current which was suppliedto lamp 9, the globule 2 will be maintained in the right-hand end of the receptacle as long as contact l|-l8 and switch S are closed.

The globule 2 may be caused to return to the left-hand end of the receptacle to extinguish lamp l0 and to light lamp 9 by simply opening contact |1l8 and closing contact I 1-l9 so that winding IE will become energized in the opposite direction to supply magnetic flux in the reverse direction.

Referring now to Figs. 10, 11, and 12, the receptacle l is again suitably supported in an inclined position by means not shown in the drawing so that globule 2 rests in the lower end of the receptacle. The usual electrodes 4 and are provided in the lower end of the receptacle but rela tively long electrodes 20 and 2| are provided in the upper end of the receptacle. Permanent magnet 3 is provided with a winding 22 so that the intensity of the magnetic flux may at times be increased.

Considering that the lamp 9 is a variable load and that the normal current supplied to the load, when switch S is closed, is not sufiicient to move globule 2 out of engagement with electrodes 4 and 5 then, when an overload occurs, the increase in current flowing through globule 2 causes the mercury to move to the right to open the circuit for lamp 9. When electrodes 20 and 2| become bridged, a circuit will be completed for winding 22 so that the magnetic flux is increased to a value suificient to maintain globule 2 in the upper end of the receptacle until switch S is opened. It is apparent, therefore, that the apparatus illustrated in Figs. 10, 11, and 12 may be utilized as an overload circuit breaker.

Although I have shown the apparatus embodying my invention as being operated by a battery which supplies direct current, it is understood that, if desired, alternating current may be used by providing a magnet of laminated construction having a suitable winding similar to that shown igr the apparatus illustrated in Figs. 10, 11, and

Although I have herein shown and described only a few forms of electrlcal apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a circuit interrupter, in combination, an elongated receptacle in a fixed position, a first pair of electrodes in one end of said receptacle and a second pair of electrodes in the other end of said receptacle, a globule of mercury for bridging said first pair of electrodes or said second pair of electrodes depending upon whether the mercury is in said one end or the other, means for passing magnetic flux through said mercury, means including said first pair of electrodes for passing an electric current in one direction through said mercury to propel the globule to the other end of the receptacle, and means including said second pair of electrodes for passing an electric current in the other direction through said mercury to propel the globule back to said one end of said receptacle.

2. In combination, an elongated receptacle fixed in an inclined position, a globule of electro-conductive liquid in said receptacle, means for passing magnetic flux through said liquid, a short electrode in contact with said liquid only when said liquid is in the lower end of said receptacle, a long electrode in contact with said liquid and extending throughout the length of the receptacle, a source of current and a load, and means connecting said load and said source of current to said electrodes to pass a current through said liquid in a particular direction whereby the currentand the flux coact to propel the liquid out of contact with said short electrode, said direction being such that the long electrode is positively charged to prevent arcing between the liquid and the short electrode thereby disconnecting current from said load.

3. In combination, an elongated receptacle fixed in an inclined position, a globule of electroconductive liquid in said receptacle, means for passing magnetic flux through said liquid, a short electrode in contact with said liquid only when said liquid is in the lower end of said receptacle,

a long electrode in contact with said liquid and extending throughout the length of the receptacle, a source of current and a load, and means connecting said load and said source of current to said electrodes to pass a current through said liquid in a particular direction whereby the current and the flux coact to propel the liquid out of contact with said short electrode, said direction being such that the long electrode is negatively charged to draw an arc between the liquid and the short electrode thereby limiting the current received by said load.

4. In combination, an elongated receptacle fixed in an inclined position, a pair of comparatively short electrodes in the lower end oi said receptacle, a pair of comparatively long electrodes in the upper end of said receptacle, a globule of electro-conductive liquid in s'aid'receptacle, means for passing magnetic flux through said liquid, means including a load for supplying energy to the short electrodes to pass electric current through the liquid to propel the globule towards the upper end of the receptacle, and means effective when said long electrodes are bridged by the liquid to pass current through the liquid to maintain the globule outof contact ,with said short electrodes. 1

5. In a circuit interrupter, in combination, a body having an elongated chamber,therein a globule of, electrically conducting liquid mounted in said chamber and movable therein from one end of said chamber to the other end thereof, a pair of electrodes associated with said body, said electrodes being arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent one end of said chamber, whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, and means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing from one of said electrodes to the other, said flux and said current coacting to initiate movement of the globule of liquid from said one end of said chamber towards the other end thereof at a speed such that the inertia of the globule causes the globule to continue to move after the flow of current through the globule ceases, whereby said globule is moved out of bridging relationship with said electrodes to thereby interrupt the circuit through said electrodes.

6. In a circuit interrupter, in combination, a body having an elongated chamber therein,aglobule of electrically conducting liquid mounted in said chamber and movable therein from one end of said chamber to the other end thereof, a pair of electrodes associated with said body, said electrodes being arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent one end of said chamber, whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing from one of said electrodes to the other, said flux and said current co-acting to initiate movement of the globule of liquid from said one end of said chamber towards the other end thereof at a speed such that the inertia of the globule causes the globule to continue to move after the flow of current through the globule ceases, whereby said globule is moved out of bridging relationship with said electrodes to thereby interrupt the circuit through said electrodes, and means operative upon movement of said globule to said other end of said chamber for effecting return movement of said globule to said one end of said chamber.

7. In a circuit interrupter, in combination, a body having an elongated chamber therein, a globule oielectrically conducting liquid mounted in said chamber and movable therein from one end of said chamber to the other end thereof, a pair of electrodes associated with said body, said electrodes being arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent one end' of said chamber, whereby a circuit is established through which current may flow from one of said electrodes to the'other through said liquid, means for passing magnetic flux through said globule of liquidin a plane generally perpen dicular to the plane in which the current flows in passing from one of said electrodes to the other, said flux and said current coacting to initiate movement of the globule of liquid from said one end of said chamber towards the other end there'- of at a speed such that the inertia of the globule causes the globule to continue to move after the flow of current through the globule ceases, where bysaid'globule is moved out of bridging'rela tionship with said electrodes to thereby interrupt the circuit through said electrodes, and other electrodes associated with said body and arranged so that they are bridged by said globule of liquid when and only when said globule of liquid is moved substantially to said other end of said chamber.

8. In a circuit interrupter, in combination, a body having an elongated chamber therein, a globule of electrically conducting liquid mounted in said chamber and movable therein from one end of said chamber to the other end thereof, two pairs of electrodes associated with said body, one of said pairs of electrodes being arranged so that they are engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent one end of said chamber whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, the other of said pair of electrodes being arranged so that they are engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent the other end of said chamber whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, the chamber, the globule of liquid, and the electrodes being arranged so that when the globule is disposed intermediate the ends of the chamber it is out of bridging relationship with both of said pairs of electrodes, and means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing between the electrodes of either of said pairs, said flux and the current flowing through said globule when the globule is at either end of said chamber co-acting to initiate movement of the globule of liquid away from said end of said chamber towards the other end thereof at a speed such that the inertia of the globule causes theglobule to continue to move after the flow of current therethrough ceases, whereby the globule is moved from the position in which it establishes a circuit between one pair of electrodes to a position in which it establishes a circuit between the other pair of electrodes.

9. In a circuit interrupter, in combination, a body having an elongated chamber therein, the

bottom wall of said chamber being inclined at anangle to the horizontal whereby the region at one end of the chamber is at a lower level than the portions of said chamber spaced from said end, a globule of electrically conducting liquid mounted in said chamber and movable therein from one end of the chamber to the other end thereof, a pair of electrodes associated with said body and arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is at the lower end of said chamber whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, and means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing from one of said electrodes to the other, said fiux and said current coacting to initiate movement of the globule of liquid away from the lower end of said chamber across said inclined wall against the force of gravity at a speed such that the inertia of the globule causes the globule to continue to move after the flow of currentthrough the globule ceases, whereby said globule is moved out of bridging relationship with said electrodes to thereby interrupt the circuit through said electrodes.

aitaooe 10. In a circuit interrupter, in combination, a body having an elongated chamber therein, the bottom wall of said chamber being inclined at an angle to the horizontal whereby the region at one end of the chamber is at a lower level than the portions of said chamber spaced from said end, a globule of electrically conducting liquid mounted in said chamber and movable therein from one end of the chamber to the other end thereof, a pair of electrodes associated with said body and arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is at the lower end of said chamber whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing from one of said electrodes to the other, said flux and said 20 current coacting to initiate movement of the globule of liquid away from the lower end of said chamber across said inclined wall against the force of gravity at a speed such that the inertia of the globule causes the globule to continue to 1 move after the flow of current through the globule ceases, whereby said globule is moved out of bridging relationship with said electrodes to thereby interrupt the circuit through said electrodes, and means operative on movement of said globule of liquid away from the lower end of said chamber to maintain said globule of liquid out of bridging relationship with said electrodes.

11. In a circuit interrupter, in combination, a

body having an elongated chamber therein, a globule of electrically conducting liquid mounted in said chamber and movable therein from one, end of said chamber to the other end thereof,

a pair of electrodes associated with said body,

said electrodes being arranged so that they are both engaged by said globule of liquid when and only when said globule of liquid is disposed adjacent one end of said chamber whereby a circuit is established through which current may flow from one of said electrodes to the other through said liquid, and means for passing magnetic flux through said globule of liquid in a plane generally perpendicular to the plane in which the current flows in passing from one of said electrodes to the other, said flux and said current coacting to initiate movement of the globule of liquid from said one end of said chamber towards the other end thereof at a speed such that the inertia of the globule causes the globule to continue to move after the fiow of current through the globule ceases, whereby said globule is moved. out of bridging relationship with said electrodes to thereby interrupt the circuit through said electrodes, awinding operative when energized to create magnetic fiux which is passed through said globule of liquid, other electrodes associated with said body and controlling the circuit through said winding, said other electrodes being arranged so that they are bridged by said globule of liquid to establish a circuit through said winding when and only when the globule of liquid is moved a predetermined distance from said one end of said chamber, the 7 12. In a circuit interrupter, in combination, a

body having an elongated chamber therein, a globule of electrically conducting liquid in said chamber, means for passing magnetic flux through said liquid, electrodes in a circuit to be controlled arranged so that they are bridged by said globule of liquid when it is at one end of said chamber whereby current may flow from one of said electrodes to the other in one direction through said liquid, other electrodes in another 10 circuit to be controlled arranged so that they are bridged by said globule 0! liquid when it is at the other end of said chamber, whereby current may flow from one to the other of said other electrodes through said liquid in the opposite direction, the magnetic flux and the current flowing through said liquid coacting to propel the liquid to and fro between the ends of the chamber. 

